High expression of enhancer of zeste homologue 2 indicates poor prognosis in patients with soft tissue sarcomas.

Enhancer of zeste homologue 2 (EZH2), a member of the polycomb group of genes, is associated with malignancy in several human cancers. The purpose of this study was to examine the association between EZH2 expression and clinicopathological factors as compared to Ki-67 expression in human soft tissue sarcomas. Expression of EZH2 and Ki-67 was immunohistochemically determined in paraffin-embedded sections from 104 soft tissue sarcomas. High expression of both EZH2 and Ki-67 was significantly correlated with distant metastasis (P<0.01), histologic grade (P<0.01) and poor prognosis (P<0.01), but not with clinicopathological factors such as age, sex, and tumor location and size. Although EZH2 expression was significantly correlated with Ki-67 expression (rs=0.65, P<0.01), multivariate analysis showed that high expression of EZH2, but not of Ki-67, was an independent factor of poor prognosis (relative risk = 2.79; P=0.02). These data suggest that expression of EZH2 is a novel and reliable prognostic marker of human soft tissue sarcomas.